Antisiphon fluid inlet means

ABSTRACT

An antisiphon fluid inlet means is provided to minimize the possibility of reverse flow of washing liquid from an automatic washer into the water piping of the building in which the washer is installed. The means comprises a housing defining an arcuate chamber therein having a tangential inlet and a tangential outlet thereto, and a vent to the atmosphere formed centrally within the housing. A flow direction means, which, in one embodiment includes a cusp formed adjacent the outlet opening from the chamber, directs a substantial portion of the fluid circulating within the chamber to the outlet opening, and directs the remainder of the fluid into the chamber for continued circulation therein. The vent is positioned out of the path of fluid circulating within the chamber and is adapted to admit air from the exterior of the housing should a suction force be exerted on the inlet, and to drain to the exterior of the housing a sufficient amount of any fluid which may backflow through the outlet to prevent fluid discharge from the chamber back through the inlet and into the water supply connected thereto.

United States Patent [72] Inventor Gerald J Kushner Louisville, Ky. [21] Appl. No. 787,045 [22] Filed Dec. 26, 1968 [45] Patented May 11,1971 [73] Assignee General Electric Company [54] ANTISIPHON FLUID INLET MEANS 10 Claims, 5 Drawing Figs.

[52] US. Cl 137/216 [51] F161 55/06, E030 1/10 [50] Field ofSearch 137/215, 216, 216.1, 216.2, 217, 218; 68/207 [56] References Cited UNlTED STATES PATENTS 2,211,459 8/1940 Dawson 137/216 3,159,174 12/1964 Searle et a1. 137/216X 3,344,800 10/1967 Parkison 137/216 3,382,885 5/1968 Cutler 137/2 16.1

Primary ExaminerRobert G. Nilson Attorneys-James E. Espe, Harry F. Manbeck, Jr. and Frank L. Neuhauser ABSTRACT: An antisiphon fluid inlet means is provided to minimize the possibility of reverse flow of washing liquid from an automatic washer into the water piping of the building in which the washer is installed. The means comprises a housing defining an arcuate chamber therein having a tangential inlet and a tangential outlet thereto, and a vent to the atmosphere.

formed centrally within the housing. A flow direction means, which, in one embodiment includes a cusp formed adjacent the outlet opening from the chamber, directs a substantial portion of the fluid circulating within the chamber to the outlet opening, and directs the remainder of the fluid into the chamber for continued circulation therein. The vent is positioned out of the path of fluid circulating within the chamber and is adapted to admit air from the exterior of the housing should a suction force be exerted on the inlet, and to drain to the exterior of the housing a sufficient amount of any fluid which may backflow through the outlet to prevent fluid discharge from the chamber back through the inlet and into the water supply connected thereto.

IIIIIA PATENTED HAY1 1 1971 I N VENTOR. GERALD :r. KUSHNER QM M H-\S ATTORNEY AN'IISIPHON FLUID INLET MEANS BACKGROUND OF THE INVENTION This invention relates generally to a fluid inlet means for supplying water to a washing machine or the like, and in particular, relates to a fluid inlet means having an improved vacuum break or antisiphon feature to minimize the possibility of reverse flow of washing liquid from the automatic washer to the water piping of the building in which the washer is installed.

It has long been recognized that when a plumbing fixture or the like is connected to the water supply of a building there is a danger reverse flow of contaminated water from the fixture to the water piping when the inlet to the fixture is below the overflow level of the fixture. Such a reverse flow is known in the art as a cross connection." Clothes washing machines, and particularly those designed for automatic operation, present opportunities for the establishment of a cross connection because-the nozzle for discharging water to the tub or washing basket in which the washing is done is frequently positioned below the overflow level thereof. Consideration must also be given to the substantial thickness of the suds which may rise well above the overflow level causing contaminates to surround a discharge nozzle positioned well above the overflow level of the washing container.

With automatic washing machines, cross connections may be caused by the onset of low or below atmospheric pressure within the water supply system connecting with the washer or by high suds pressure within the washer itself. Low transient supply system pressures frequently occur in the complex plumbing systems of large apartment buildings due to the opening and closing of values by the occupants. Furthermore, below atmospheric pressure situations may occur in almost any plumbing system due to conduit failure or inadvertent draining. For example, consider a house in which an automatic washer is in operationon the first floor. As may commonly occur, assume that the washer is in the agitation cycle and its water admission control valve, as well as all other faucets in the house, are closed. Should a plumbing failure occur in the basement of this house, due to the fact that all the water outlets are closed, water will only drain from the upper portion of the water supply system, forming a vacuum therein. When the washers water admission control valve opens to admit water for rinsing and the like, the vacuum of the household water supply system will cause the washer water inlet system to experience a suction force tending to draw contaminants from the washing basket into the household water piping. ln somewhat similar manner, some detergents may also induce cross connections by causing increased pressure within the washing container resulting the suds and other contaminants being forced to backflow into the water supply piping.

It recognition of these problems, most plumbing codes now require that water inlets to automatic washers incorporate an antisiphon or vacuum break provision providing an airgap upstream of the water discharge nozzle. By this arrangement, should the building's water supply system experience an internal pressure less than that within the washing basket, no direct suction force will be exerted through the dischargenozzle and no contaminates will be exerted through the discharge nozzle and no contaminates will be drawn from the washing basket and into the water supply system. Furthermore, most such plumbing codes specify, in substance, that the vacuum break should have an inlet opening, an outlet opening, and a chamber having a vent or opening to the atmosphere, and that the vent opening should be positioned at least 1 inch below the inlet opening. By this arrangement, should washing fluid backflow from the outlet into the chamber, it will drain from the chamber through the vent opening rather than backflow into the inlet and the water supply system connected thereto.

A number of vacuum break configurations corresponding with plumbing code requirements are now being incorporated by the various manufacturers in their automatic washers. However, because the codes specify that the vacuum break through the chamber past the atmospheric opening and into the outlet opening with minimal momentum loss. The restricted inlet opening, however, has been found to be subject to calcium deposits as small quantities of water tend to settle therein or discharge therefrom on a slow, drop by drop,

basis during periods of nonuse. Such deposits tend to deter the operation of the inlet opening and frequently cause the formation of a nonlaminar flow within the chamber of the vacuum break with consequential splashing and discharge results not only in ineffective delivery of water to the washing basket discharge nozzle but also in undesirable venting of substantial water basket discharge nozzle but also in undesirable venting of substantial to the interior of the washer cabinet through the atmospheric opening.

. It is, accordingly, an object of this invention to provide an improved fluid inlet means for use in a washing machine or the like and having a vacuum break tominimize cross connection even though the washing basket discharge nozzle may become submerged in water or in suds floating thereon.

It is a further object to provide such a fluid inlet means which is simple and inexpensive in design, and which will overcome the problem of splashing due to the formation of impurity deposits within the inlet opening to the vacuum break.

It is still another object to provide such a device which prevents unnecessary discharge of water through the atmospheric opening as may be caused by splashing by recirculating any nonlaminar discharge from the inlet opening through the chamber of the vacuum break and toward the outlet thereof.

SUMMARY OF THE INVENTION Briefly stated, in accordance with one aspect of the present invention, there is provided fluid inlet means comprising a housing defining a chamber therein. An inlet means directs fluid from a source of fluid under pressure into the chamber for circulation therein in one rotational direction, and an outlet means tangentially discharges at least a portion of the fluid circulating within the chamber. A vent means is positioned out of the path of the circulation fluid to provide communication between the chamber and the exterior of the housing. The vent means is adapted to admit air from the exterior of the housing should a suction force be exerted on the inlet means. Furthermore, should a suction force be exerted on the inlet means, the vent-means is adapted to drain to the exterior of the housing a sufl'icient amount of any fluid backflowing through the outlet to prevent such fluid from backflowing into the inlet means and the source of fluid associated therewith.

BRIEF DESCRIPTION OF THE DRAWING While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed the invention will be better understood from the following description of the preferred embodiments taken in connection with the accompanying drawing, in which:

FIG. I is a partial, schematic, elevational view of a clothes washing machine including one embodiment of the fluid inlet means of the present invention;

1 FIG. 2 is a sectional view of the fluid inlet means of FIG. 1;

FIG. 3 is a view taken along line 33 of FIG. 2',

FIG. 4 is a sectional view of an alternate embodiment of my device; and

FIG. 5 is a view taken along line 5-5 of FIG. 4.

3 DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawing, and initially to FIG. 1 thereof, there is illustrated an agitator-type vertical-axis automatic clothes washer 10. The washer normally includes a suitable appearance and protective outer cabinet which, in the interest of clarity, has been omitted from the drawing. The washer may include a rigidly mounted imperforate tub 11 having a perforate washing basket or container 12 rotatably supported therein for washing and rinsing clothes therein and for centrifugally extracting liquid therefrom. At the center of basket 12 there is provided an agitator 13 which includes a center post 14 having a plurality of curved water circulating vanes 15 joined at their lower end to form an outwardly flared skirt l6. Normally a resilient gasket (not shown) is provided between the upper edge of tub 11 and the appearance cabinet to prevent moisture from escaping into the space between the tub and the cabinet.

Both the clothes basket 12 and the agitator 13 are rotatably mounted. The basket is mounted on a flange 17 of a hub 18 and the agitator 13 in mounted on a shaft 19 which extends upwardly through the hub 18 and through the center post 14 and is secured to the agitator so as to drive it. During one possible cycle of operation of the washer 10, liquid is introduced into the tub 11 and basket 12, and the agitator is then oscillated around its axis to wash the clothes within the basket. After a predetermined period of this washing action, basket 12 is rotated at high speed to centrifugally extract the washing liquid from the fabrics. Following this extraction operation, a supply of clean liquid is introduced into the basket for rinsing the fabrics and the agitator is again oscillated. Finally, the basket is once more rotated at high speed to extract the rinse liquid.

The basket 12 and agitator 13 may be driven by any suitable means. By way of example, I have shown them as driven from a reversible motor 20 through a drive mechanism including a clutch 21 mounted on the motor shaft. A suitable belt 22 transmits power from clutch 21 to a transmission assembly 23 through a pulley 24. Thus, depending upon the direction of motor rotation, the pulley 24 of transmission 23 is driven in opposite directions. The transmission 23 is so arranged that it supports and drives both the agitator drive shaft 19 and the basket mounting hub 18. When motor 20 is rotated in one direction, the transmission causes agitator 13 to oscillate and, when motor 20 is driven in the opposite direction, the transmission rotates the clothes basket 12 and agitator 13 together at high speed for centrifugal fluid extraction. Because the specific type of transmission used does not form a part of the present invention, reference is made to US. Pat. No; 2,844,225 issued July 22, 1958 to Mr. James R. Hubbard et al. and assigned to the assignee of the instant invention. That patent disclosed in detail the structural characteristics of a transmission assembly suitable for use in the illustrated machine.

ln addition to operating the transmission 23 as described, motor 20 also provides a direct drive through a flexible coupling 25 to a pump structure 26 having an inlet connected by conduit 27 to an opening 28 formed in the lowermost part of tub 11 and an outlet connected to by a conduit 29 to a suitable drain (not shown). With this structure, when the motor is operating so as to provide agitation, pump structure 26 is rotated in reverse direction and is substantially inoperative. Conversely, when the motor is reversed so as to rotate the basket 12 and agitator 13 together at high speed to centrifugally extract fluid from fabrics in the basket, pump structure 26 will draw liquid in from opening 28 through conduit 27 and discharge it through conduit 29 to drain.

In order to accommodate the movement which occurs between transmission 23 and tub 11, which also represents vibrational movement between basket 12 and tub 11, without any danger of fluid leakage between them, the stationary tube 11 is joined to the upper part of transmission 23 by a flexible boot member 30. A member of thistype is described and claimed in US. Pat. No. 2,959,966 issued Nov. 15, 1960 to Mr. John Bochan and assigned to the assignee of the instant invention.

Hot and cold water may be supplied to the machine through conduits 31 and 32 which are adapted to be connected respectively to sources of hot and cold water (not shown). Conduits 31 and 32 extend into a conventional mixing valve structure 33 having solenoids 34 and 35 and being connected to a hose 36. In a conventional manner selective or concurrent energization of solenoids 34 and 35 will provide the passage of hot, cold or warm water from the mixing valve 33 through the hose 36. Hose 36 connects with a fluid inlet means 37 which is the subject of my invention, the construction and operation of which will be described below in detail. lnlet 37, in turn, connects with another hose 38 which communicates with a discharge nozzle 39. Nozzle 39 is designed to break up and spread out the flow of fluid from hose 38 and to discharge the resulting gentle stream directionally into basket 13. A water trap 40 may be formed within hose 38 to provide a liquid barrier to suds tending to enter nozzle 39 and travel down hose 38 toward vacuum break 37.

lt will be understood that, while the description of the machine thus far excludes a substantial amount of detail relating to the supporting structure and the drive, and does not shown all the valves and particular controls normally provided on modern domestic washing machines, the elimination and simplification of these items are primarily for the purpose of permitting a clear explanation of the inventive concept set forth below. It will be recognized that the omitted details are conventional items included in virtually all domestic washing machines, whose structure and positioning is well known to these skilled in the art.

Referring now more particularly to FIGS. 2 and 3 wherein one embodiment of vacuum break 37 is illustrated, it will be seen that the outer structure of the vacuum break comprises a housing 41 having first and second end walls, 42 and 43 respectively, and a sidewall 44 connecting with end walls 42 and 43 to define a chamber 45 therein. Formed integral with housing 41 is an inlet means 46 and an outlet means 47. In cross section, sidewall 44 is of substantially circular configuration exposing toward chamber 45 a first arcuate wall portion 48 extending between inlet means 46 and outlet means 47, and a second arcuate wall portion 49 continuing from outlet means 47 back to inlet means 46.

lnlet means 46 is adapted to direct fluid from a source of fluid under pressure tangentially into chamber 45, and comprises a tangential inlet opening 50 formed substantially adjacent the uppermost point of chamber 45. A passageway 51 extends inlet opening 50 through an elongated cylindrical formation 52 adapted to engage hose or flexible conduit 36 which, previously described, connects through appropriate valving to a source of fluid under pressure. Fluid entering chamber 45 through inlet opening 50 circulates in the direction of flowstream arrows 53 along arcuate wall portion 48 toward outlet means 47.

Outlet means 47 is adapted to discharge tangentially from chamber 45 at least a portion of the fluid circulating along wall portion 48 in the direction of flowstream 53, and comprises an outlet opening 54 formed tangential to wall portion 48 at a position lower than that of inlet opening 50. ln order to provide minimal flow resistance to the fluid discharging through outlet means 47, and to provide for some measure of expansion of flowstream 53 within chamber 45, outlet opening 54 is a larger cross-sectional area than inlet opening 50, and connects with a circular passageway 55 of larger cross-sectional area than inlet passageway 51. Outlet opening 54 and passageway 55 are directed substantially vertically downwardly. Passageway 55 terminates in an elongated cylindrical formation 56 adapted to engage hose or flexible conduit 38 which, as previously described, connects with discharge nozzle 39 positioned to deliver fluid to washing basket 12.

Ideally, in one embodiment of my invention, the above described path of fluid flow from inlet means 46 along wall portion 48 and out through outlet means 47 is the only flow which occurs when water is being admitted to the washing basket 12. However, due to the fact that deposits of calcium or other minerals may tend to form within inlet passageway 51 and inlet opening 50, the flowstream 53 may be only partially laminar and include spitting offshoots or turbulent layers which tend to widen flowstream 53 such that it is of greater cross-sectional area than outlet opening 54. To provide for a significant measure of this widening flowstream effect, a flow direction means may be incorporated adjacent outlet opening 54. In the embodiment of FIG. 2, such flow direction means comprises flow splitter 57 having a pointed portion 58 and a funnel-shaped arcuate wall portion 59 which operate to funnel the portion of flowstream 53 to the outside of point 58 into outlet opening 54, and to redirect the portion of flowstream 53 which is inside point 58 back into chamber 45, as is indicated by flowstream 60. Flowstream 60 is directed in an arcuate path through chamber 45 along arcuate wall portion 49 toward the region of inlet opening 50 where flowstream 60 rejoins inlet flowstream 53 at such an angle as to greatly enhance its chances of discharge from chamber 45 through outlet opening 54, and to reduce the expansion of inlet fluid 53 due to spitting offshoots or turbulence. In this manner, the flow path of fluid through my device tends to remain laminar, and turbulent offshoots of fluid quickly become self-correcting permitting very little splashing of fluid within the central region of chamber 45.

Formed within this central region of chamber 45 is a vent means 61 comprising an opening 62 formed in end wall 42 to the exterior of housing 41. As housing 41 is mounted within a portion of the machine appearance cabinet which is assured of 1 exposure to atmospheric pressure, vent means 61 exposes chamber 45 and the fluid flowing therein to atmospheric pressure. A drip lip 63 is formed adjacent the upper portion of opening 62 to prevent entry into opening 62 of any fluid which may fall from inlet opening 50 during the initiation or termination of fluid flow to washing basket 12. 7

Opening 62 is positioned a distance 64 beneath inlet opening 50, the distance 64 at least 1 inch as required by-plumbing codes. Furthermore, opening 62 is of greater area than outlet opening 54. By this arrangement, should any fluid backflow from outlet means 47 into chamber 45, a sufficient amount thereof will be drained to the exterior of the housingthrough opening 62 to prevent such fluid from backflowing into inlet means 46. The distance 64 being at least 1 inch is to assure that backflowing fluid will not rise within chamber 45 sufficiently for suds floating thereon to enter inlet opening 50. Opening 62 also serves in a second way to prevent cross connections. Should a suction force be exerted on inlet means 46 through hose 36, opening 62 will admit air from the exterior of housing 41 thereby alleviating the transmittal of such suction force to outlet means 47 and the consequential drawing of washing fluid into chamber 45 at such a rate as to cause the backflowing fluid to be directed by arcuate wall portion 48 into inlet opening 50.

In order to drain noncirculating fluid from chamber 45 which may tend to collect therein due to gradual drop by drop flow from inlet opening 50 during periods of nonuse, or due to fluid backflow, a conduit means 65 is formed within housing 41 to connect with the lowermost point of chamber 65 and drain therefrom into outlet means 47.

Reference is made to FIGS. 4 and 5 wherein another embodiment of my device is illustrated. In this embodiment, vacuum break 66 comprises a housing 67 having first and second inwardly concave end walls, 68 and 69 respectively, and a sidewall 70 connecting therewith to define a chamber 71. Formed integral with housing 67 is an inlet means 72 and an outlet means 73. Sidewall 70 exposes toward chamber 71, a first arcuate wall portion 74 and a second arcuate wall portion 75.

6 Inlet means 72 is adapted to direct fluid from a source of fluid under pressure tangentially into chamber 71, and comprises a tangential inlet opening 76 formed substantially adjacent the uppermost point of chamber 71. Inlet opening 76 is.

shown as comprising a slot which connects with a passageway 77 extending through an elongated cylindrical formation 57 adapted to engage a flexible conduit. Fluid entering chamber 71 through inlet opening 76 circulates in the direction. of flowstream arrows 79 alongarcuate wall portion 74 toward outlet means 73.

Outlet means 73 comprises an outlet opening 80 formed tangential to wall portion 74 at a position lower than that of inlet opening 76. Outlet opening 80 is of larger area than inlet opening 76, and connects with a passageway 81 of larger area than inlet passageway 77. Outlet opening 80 and passageway 81. are directed substantially vertically downwardly, passageway 81 terminating in an elongated, cylindrical formation 82 adapted to engage a flexible conduit. As will be readily apparent, inlet opening 76, passageway 72, outlet opening 80 and passageway 81 may take any of a variety of cross-sectional configurations, so long as the relative areas thereof provide minimal flow resistance to the fluid discharging from chamber 71.

In the embodiment of FIGS. 4 and 5, a flow direction means in the form of a cusp 83 is incorporated adjacent outlet opening 80, whereby a portion of flowstream 79 will be caused to assume a vortical flow directed toward outlet opening 80 as indicated by arrow 84. Such flow direction means provides for a widening of the flowstream 79 during its travel through chamber 71 and encourages a substantial portion of flowstream 79 to discharge from chamber 71 through outlet opening 80.'The remainder of flowstream 79 which does not exit through discharge opening 80 is redirected back into chamber 71 where it flows in an arcuate path therethrough along arcuate wall portion 76 toward the region of inlet opening 77. Formed within the central region of chamber 75 is a vent means 85 comprising an opening 86 through end wall 68 to the exterior of housing 67. A drip lip 87 is formed adjacent the upper portion of opening 86 to prevent entry into opening 86 of any fluid which may fall from inlet opening 76 during the initiation or termination of fluidflow. Drip lip 87 is seen to comprise a horizontal portion 88 adjoining a vertical wall portion 89 extending upwardly and downwardly therefrom. As will be evident, drip lip 87 may be designed to perform its function by assuming various configurations wherein vertical wall portion 89 may. extend only downwardly from horizontal portion 88, or only upwardly from horizontal portion 88 or wherein vertical wall portion 89 is nonexistent as in the embodiment of FIGS. 2 and 3.

Opening 86 is positioned at 'a distance 90 of at least 1 inch beneath opening 76, where so required by plumbing codes. Furthermore, opening 86 is of greater area than outlet opening 80. As will be readily apparent, opening 86 may take the form of one or more openings disposed in either of the end walls 68 and 69, the total area of which should be greater than that of outlet opening 80 in order to assure adequate drainage capacity from chamber 71 to prevent the filling of chamber 71 upon backflow of fluid from outlet means 73. In order to drain noncirculating drain fluid from chamber 71, a conduit means 91 is formed within housing 67 to connect with the lowermost point of chamber 71 and drain therefrom into outlet means 73.

It is within the scope of my invention to so modify the flow direction means associated withthe outlet opening from the chamber of my vacuum break so as to insure that a portion of the inlet flow to the chamber will be caused to circulate therein. Such an alteration of the flow direction means may be advantageous in some applications wherein it is desirable to maintain a high inlet pressure.

The vacuum breakof my invention is adapted to be constructed from any of a variety of materials. For example, either of the embodiments illustrated may bemolded from two or more pieces of polypropyleneplastic heat bonded together.

As we previously mentioned, my system is particularly adapted for use with an automatic washer wherein it is desireable to provide a vacuum break to minimize the possibility of a cross connection between the washer and the water supply system in the building in which it is mounted, and wherein it is desirable to minimize splashing from the atmospheric opening thereof as may be caused by deposits forming in the inlet thereto. From the foregoing description it should now be apparent that the present invention provides a circulating fluid flow within a vacuum break chamber wherein spitting fluid offshoots or turbulent flow is self-correcting and the flow therein tends to remain laminar whereby splashing is minimized with a minimal decease in fluid momentum passing therethrough.

As will be evident from the foregoing description, certain aspects of the invention are not limited to the particular details of the construction of the examples illustrated, and it is contemplated that various other modifications or applications will occur to those skilled in the art. it is therefore intended to cover such modifications and applications as do not depart from the true spirit and scope of the invention.

I claim:

1. An antisiphon fluid inlet means comprising:

a housing defining a chamber therein;

inlet means positioned to direct fluid from a source of fluid under pressure tangentially into said chamber for circulation therein in one direction;

said inlet means comprising at least one inlet opening into said chamber, said inlet opening being directed substantially horizontally and positioned adjacent to the uppermost point of said chamber;

outlet means positioned to discharge tangentially from said chamber at least a portion of the fluid circulating therein in said one direction;

said outlet means comprising at least one outlet opening into said chamber, said outlet opening being directed substantially vertically downwardly and being positioned below said inlet opening, the area of said outlet opening being greater than the area of said inlet opening;

vent means venting said chamber to the exterior of said lating fluid flow into said outlet opening and to recirculate the remainder of said flow within said chamber.

2. The vacuum break of claim 1 additionally comprising conduit means to drain noncirculating fluid from the lowermost point of said chamber.

3. The vacuum break of claim 2 wherein said conduit means drains into said outlet means.

4. The vacuum break of claim 1 wherein said flow direction means includes a cusp formed adjacent said outlet opening.

5. A vacuum break comprising:

a housing comprising first and second substantially vertically disposed end walls and an arcuate sidewall connecting with said end walls to define an arcuate chamber therein;

inlet means adapted to connect 'to a source of fluid under pressure, and comprising an opening through said arcuate sidewall to direct fluid tangentially into said chamber for circulation therein in one rotational direction;

outlet means comprising an opening through said arcuate sidewall to discharge tangentially from said chamber at least a portion of the fluid circulating therein in said one rotational direction;

flow direction means to direct a substantial portion of the circulating fluid flow within said chamber into said outlet opening and to recirculate the remainder of said flow within said chamber conduit means formed within said housing to drain noncirculating fluid flow from the lowermost point of said chamber into said outlet means; and

at least one opening to the atmosphere from said chamber positioned out of the path of the circulating flow at a location spaced upwardly from said lowermost point of said chamber and downwardly from said inlet means.

6. The vacuum break of claim 5 wherein the area of said opening to the atmosphere is at least as large as the area of said outlet opening which, in turn, is greater than the area of said inlet opening.

7. The vacuum break of claim 6 wherein said inlet opening is directed substantially horizontally and said outlet opening is directed substantially vertically downwardly, said outlet opening being positioned at a location below said inlet opening.

8. The vacuum break of claim 7 wherein said opening to the atmosphere is formed through at least one of said end walls substantially centrally thereof.

9. The vacuum break of claim 8 wherein said flow direction means includes a cusp fonned adjacent said outlet opening.

10. The vacuum break of claim 8 additionally including a drip lip to prevent fluid falling from said inlet opening from entering said opening to the atmosphere. 

1. An antisiphon fluid inlet means comprising: a housing defining a chamber therein; inlet means positioned to direct fluid from a source of fluid under pressure tangentially into said chamber for circulation therein in one direction; said inlet means comprising at least one inlet opening into said chamber, said inlet opening being directed substantially horizontally and positioned adjacent to the uppermost point of said chamber; outlet means positioned to discharge tangentially from said chamber at least a portion of the fluid circulating therein in said one direction; said outlet means comprising at least one outlet opening into said chamber, said outlet opening being directed substantially vertically downwardly and being positioned below said inlet opening, the area of said outlet opening being greater than the area of said inlet opening; vent means venting said chamber to the exterior of said housing, said vent means being positioned out of the path of fluid circulating in said one direction to admit air from the exterior of said housing should a suction force be exerted on said inlet means, and to drain to the exterior of said housing a sufficient amount of any fluid backflowing through said outlet to prevent such fluid from backflowing into said inlet means and the source of fluid associated therewith; and flow direction means to direct at least a portion of the circulating fluid flow into said outlet opening and to recirculate the remainder of said flow within said chamber.
 2. The vacuum break of claim 1 additionally comprising conduit means to drain noncirculating fluid from the lowermost point of said chamber.
 3. The vacuum break of claim 2 wherein said conduit means drains into said outlet means.
 4. The vacuum break of claim 1 wherein said flow direction means includes a cusp formed adjacent said outlet opening.
 5. A vacuum break comprising: a housing comprising first and second substantially vertically disposed end walls and an arcuate sidewall connecting with said end walls to define an arcuate chamber therein; inlet means adapted to connect to a source of fluid under pressure, and comprising an opening through said arcuate sidewall to direct fluid tangentially into said chamber for circulation therein in one rotational direction; outlet means comprising an opening through said arcuate sidewall to discharge tangentially from said chamber at least a portion of the fluid circulating therein in said one rotational direction; flow direction means to direct a substantial portion of the circulating fluid flow within said chamber into said outlet opening and to recirculate the remainder of said flow within said chamber; conduit means formed within said housing to drain noncirculating fluid flow from the lowermost point of said chamber into said outlet means; and at least one opening to the atmosphere from said chamber positioned out of the path of the circulating flow at a location spaced upwardly from said lowermost point of said chamber and downwardly from said inlet means.
 6. The vacuum break of claim 5 wherein the area of said opening to the atmosphere is at least as large as the area of said outlet opening which, in turn, is greater than the area of said inlet opening.
 7. The vacuum break of claim 6 wherein said inlet opening is directed substantially horizontally and said outlet opening is directed substantially vertically downwardly, said outlet opening being positioned at a location below said inlet opening.
 8. The vacuum break of claim 7 wherein said opening to the atmosphere is formed through at least one of said end walls substantially centrally thereof.
 9. The vacuum break of claim 8 wherein said flow direction means includes a cusp formed adjacent said outlet opening.
 10. The vacuum break of claim 8 additionally including a drip lip to prevent fluid falling from said inlet opening from entering said opening to the atmosphere. 